Document Type : Primary Research paper
Post Graduate student, Department of Civil Engineering, PSG College of Technology, Coimbatore 641004, India
Assistant Professor, Department of Civil Engineering, PSG College of Technology, Coimbatore-641004, India
Concrete is a construction material used widely due to its high compressive strength and durability.Good concrete is made out of specific proportions of cement, fine aggregate, coarse aggregate, and water. Despite its wide use, in recent days pozzolanic materials like Ground Granulated Blast Furnace Slag (GGBS), fly ash, rice husk ash are used as partial replacement in concrete to reduce the environmental effects caused during cement manufacturing and to effectively use industrial waste material as the replacement to cement. For maintaining the proper moisture conditions and to promote optimum cement hydration curing must be done immediately after placement. Enough water needs to be present in the concrete mix for the hydration of cement to take place. The Self-curing technique provides the additional moisture in concrete for more effective hydration of cement and also self-desiccation can be reduced. Self-curing agents minimize the evaporation of water from concrete thereby increases the water retention capacity. Internal curing materials such as lightweight aggregate, super absorbent polymer, shrinkage reducing admixtures, lightweight sand and wood powder improves the strength as well as durability of concrete, reduces permeability and shrinkage, and improve the rheology of concrete.
In this project, GGBS is used as a pozzolanic material in concrete and the cement is replaced by GGBS at 50% by weight of cement. For better hydration and strength development, Super Absorbent Polymer (SAP) is used as an internal curing agent. The effect of Super Absorbent Polymer (SAP) on compressive strength, split tensile strength and flexural strength were studied by varying the percentage of SAP by weight of cement from 0% to 0.4% in the order of 0.1% for M25 grade of concrete. From the test results, it was found that 0.3% of SAP was optimum for achieving maximum strength.